Answer:
30.7 ft
Step-by-step explanation:
<em>An equilateral triangle with area 43.5 has a height of 8.68 not 8.5</em>
<em>I will do the problem as written even though it is not a possible equilateral triangle</em>
<em>---------------------------------------------</em>
a = (1/2)bh
43.5 = (1/2)b(8.5)
43.5 = 4.25b
b = 43.5/4.25
b = 10.2352941176
-----------------------
p = 3b
p = 3 * 10.2352941176
p = 30.7058823528
~ 30.7 ft
If there is 20 pencils there will be 5 erasers 20:5
Remark
I don't know exactly what level you are in, but the obvious factors are
y = 2x*(x^3 + 11x + 30)
This gives one more factor somewhere around x = -11.3 . Notice that the minimum is around - 3000 or so. I don't think anyone is going to try and take this any further. My calculator figures out cubics and gives an answer of -11.23. There are two other roots but they are a complex pair.
Answer
factor 1: 2x
factor 2: x^3 + 11x^2 + 30
